000
AXPZ20 KNHC 112209 CCA
TWDEP 

TROPICAL WEATHER DISCUSSION...CORRECTED 
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC FRI FEB 11 2011

CORRECTED GULF OF CALIFORNIA ENDING TIME FRAME FOR WINDS

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2115 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS IS CENTERED ALONG 3N78W
2N91W 5N105W 6N115W 8N127W...THEN RESUMES NEAR 6N124W TO 5N140W.
NO SIGNIFICANT CONVECTION IS NOTED.

...DISCUSSION...

ALOFT...A STRONG POSITIVELY TILTED MID TO UPPER LEVEL TROUGH 
AXIS EXTENDS FROM SE ARIZONA TO 26N123W TO 25N131W AND TO AN
ELONGATED CYCLONIC CIRCULATION NEAR 21N138W. A SUBTROPICAL JET
STREAM BRANCH WITH CORE SPEEDS IN THE RANGE OF 60-80 KT E OF THE 
TROUGH CONTINUES TO ADVECT MID TO UPPER LEVEL MOISTURE FROM THE
DEEP TROPICS NORTHEASTWARD TO ACROSS SOUTHERN BAJA CALIFORNIA 
PENINSULA AND TO OVER MUCH OF NORTHERN AND CENTRAL MEXICO.
TO THE N OF THE TROUGH...N OF THE AREA...A LARGE ANTICYCLONE 
MOVING E IS IDENTIFIED NEAR 34N127W WITH ALLOWING FOR A BROAD
AREA OF ANTICYCLONIC FLOW TO EXIST OVER THIS PORTION OF THE AREA
N OF THE TROUGH. MODERATE SUBSIDENCE IS KEEPING A RATHER STABLE
AND DRY ATMOSPHERIC ENVIRONMENT IN PLACE OVER MUCH OF THE AREA N 
OF THE TROUGH AS NOTED BY THE BROKEN STRATOCUMULUS CLOUD FIELD 
LOCATED N OF 20N AND W OF 120W...AND CLEAR SKIES N OF 20N AND
E OF 120W. OVER THE CENTRAL PORTION OF THE AREA...A MID TO UPPER
LEVEL TROUGH EXTENDS FROM 20N136W SE TO 13N129W TO NEAR 9N123W.
THIS TROUGH DEVIATES THE UPPER LEVEL FLOW SOME WITH THE ABOVE
JET STREAM SE TOWARDS 100W RESULTING IN A ZONE OF UPPER LEVEL
DIFFLUENCE FROM 3N TO 14N BETWEEN 110W-121W.

WELL TO THE NW OF THE DISCUSSION IS A RATHER ROBUST DEEP LAYER 
TROUGH QUICKLY MOVING E. THIS TROUGH IS FORECAST TO CLIP THE 
FAR NW CORNER OF THE AREA LATE SAT INTO SUN AS THE BROAD 
AREA OF ANTICYCLONE AHEAD OF IT MOVES INLAND THE WESTERN AND
CENTRAL U.S.

AT THE SURFACE...A 1025 MB HIGH CENTERED LOCATED N OF THE AREA
NEAR 34N127W IS EMBEDDED WITHIN A RIDGE AXIS WHICH EXTENDS 
SOUTHWESTWARD ACROSS THE NW PORTION OF THE DISCUSSION AREA TO 
JUST EAST OF THE HAWAIIAN ISLANDS NEAR 20N145W. THE HIGH AND 
RIDGE AXIS WILL MIGRATE SLOWLY E THROUGH THE NEXT 24 HOURS AS
THE UPPER LEVEL ANTICYCLONE SHIFTS E.

A SURFACE TROUGH ANALYZED FROM 9N127W TO 4N134W IS MOVING W ABOUT
13 KT. SCATTERED MODERATE CONVECTION IS NOTED TO THE E OF THE 
TROUGH FROM 5N TO 9N AND BETWEEN 121W AND 124W...AND IS BEING 
FURTHER ENHANCED BY THE UPPER LEVEL DIFFLUENCE E OF THE MID/UPPER
LEVEL DESCRIBED ABOVE. THE INTERACTION BETWEEN THE SURFACE TROUGH
AND THE ZONE OF HIGH PRES TO ITS N IS MAINTAIN A TIGHT PRES
GRADIENT MAINLY W OF THE TROUGH WHERE NE TO E 20 TO 25 KT ARE 
EVIDENT WITHIN 180 W OF THE TROUGH...AND E OF THE TROUGH FROM
9N TO 15N BETWEEN 114W AND THE TROUGH. THE AREA OF STRONGER 
TRADES WILL GRADUALLY SHIFT NE AS THE TROUGH SLIDES WESTWARD 
OVER THE NEXT 48 HOURS.

GAP WINDS...
GULF OF TEHUANTEPEC...COLD AIR CONTINUES TO SURGE THROUGH THE 
CHIVELA PASS ACROSS THE ISTHMUS OF TEHUANTEPEC WITH WINDS THIS 
MORNING REMAINING BELOW GALE FORCE IN THE 20 TO 30 KT RANGE. 
HOWEVER...A REINFORCING SURGE OF COLD AIR IS EXPECTED TO ARRIVE 
LATER TODAY WITH WINDS REACHING STORM FORCE BY LATE SAT. A 
STRONG 1032 MB HIGH WILL CENTER OVER THE NW GULF OF MEXICO AND 
THE ASSOCIATED INCREASED PRESSURE GRADIENT OVER THE SW GULF OF 
MEXICO WILL INDUCE THE STORM FORCE WINDS THROUGH EARLY SUN WITH 
SEAS BUILDING TO 18 FT.

GULF OF PAPAGAYO...WINDS WILL CONTINUE TO PULSE TO 20 KT DURING 
THE NEXT 24 HOURS WITH ENHANCED DRAINAGE FLOW OFF THE CENTRAL 
AMERICA LANDMASS. EASTERLY TRADE WINDS WILL INCREASE IN THE 
WESTERN CARIBBEAN SEA BY EARLY SAT WHICH WILL ALLOW FOR WINDS TO 
INCREASE TO 20 TO 25 KT IN THE GULF OF PAPAGAYO THROUGH THE 
REMAINDER OF THE FORECAST PERIOD. 

GULF OF PANAMA...EASTERLY TRADE WINDS IN THE CARIBBEAN SEA ARE
ALREADY FILTERING THROUGH THE ISTHMUS OF CENTRAL AMERICA INTO
THE FAR EASTERN PACFIC AS NLY FLOW THROUGH THE GULF OF PANAMA
AS 20 KT N WINDS. THESE WINDS ARE CONFINED TO N OF 6N BETWEEN
78W AND 80W...AND ARE EXPECTED TO CONTINUE THROUGH SUN WITH 
LITTLE CHANGE.

GULF OF CALIFORNIA...A TIGHT PRES GRADIENT BETWEEN HIGH PRES 
OVER THE U.S. INTERMOUNTAIN WEST AND SURFACE TROUGHING OVER NW 
MEXICO IS GENERATING 20 KT NW TO N WINDS WHICH ARE FUNNELING 
THROUGH THE GULF OF CALIFORNIA. WINDS ARE EXPECTED TO INCREASE 
BY EARLY SAT TO 25 KT AS THE HIGH OVER THE U.S. STRENGTHENS 
SLIGHTLY...THEN DIMINISH ON THE SUN AFTERNOON.

$$
AGUIRRE